frustum.cpp

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/*
 * frustum.cpp
 *
 * Copyright (C) 2009  Thomas A. Vaughan
 * All rights reserved.
 *
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the <organization> nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THOMAS A. VAUGHAN ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THOMAS A. VAUGHAN BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
 * Retrieves view frustum from OpenGL matrices.  See frustum.h
 */

// includes --------------------------------------------------------------------
#include "frustum.h"                    // always include our own header first!

#include <math.h>

#include "wave-glut.h"



namespace glut {


static const float s_radiansPerDegree   = M_PI / 180.0;


////////////////////////////////////////////////////////////////////////////////
//
//      static helper methods
//
////////////////////////////////////////////////////////////////////////////////



////////////////////////////////////////////////////////////////////////////////
//
//      public API
//
////////////////////////////////////////////////////////////////////////////////

void
getViewFrustum
(
IN const camera_t& camera,
IN const Viewer& viewer,
OUT frustum_t& f                ///< view frustum
)
throw()
{
        // just use the basic geometry libraries
        ASSERT(createViewFrustum(viewer.getPosition(),
                viewer.getFacing(),
                viewer.getUp(),
                camera.getFovy() * s_radiansPerDegree,
                camera.getZNear(),
                camera.getZFar(),
                camera.getAspect(),
                f),
            "Failed to create view frustum--bad inputs?");
}



void
drawFrustumEdges
(
IN const frustum_t& f,
IN const glut_color_t& c
)
throw()
{
        // save existing color and lighting
        int oldLighting;
        glGetIntegerv(GL_LIGHTING, &oldLighting);
//      DPRINTF("Old lighting: %d", oldLighting);
        if (oldLighting) {
                glDisable(GL_LIGHTING);
        }
        float oldColor[4];
        glGetFloatv(GL_CURRENT_COLOR, (GLfloat *) oldColor);

        // set new color and draw
        glColor4b(c.red, c.green, c.blue, c.alpha);
        glBegin(GL_LINES);
        point3d_t p0, p1;
        for (int i = 0; i < frustum_t::eEdgeCount; ++i) {
                f.getEdge(i, p0, p1);
                glVertex3fv((GLfloat *) &p0.x);
                glVertex3fv((GLfloat *) &p1.x);
        }
        glEnd();

        // restore color and lighting
        glColor4fv((GLfloat *) oldColor);
        if (oldLighting) {
                glEnable(GL_LIGHTING);
        }
}



};      // glut namespace